It popped into my head a few days ago that Technorati could do something very similar to their blog search engine for bulletin boards. How?
- Bulletin boards can provide RSS feeds of their content, on a per-forum basis. I've installed this functionality for phpBB and vBulletin, and there's not that much to it.
- Bulletin board software usually has BBCode, or quick markup for inserting HTML into a discussion post. You then just have to add a BBCode markup item for "tags".
For example,
[tag]{param}[/tag]
would get translated to: